1. Field of the Invention
The present invention relates to an improved inertial exerciser and entertainment device which uses inertia to amplify exercise performed with the device.
2. Description of Background Information
Some conventional inertial exercisers, such as the exercisers disclosed in U.S. Pat. Nos. 4,714,946; 4,513,963; and No. 4,043,553; include eccentric weights. For example, U.S. Pat. No. 4,714,946 discloses an exerciser including a disk provided with two opposed handles. U.S. Pat. No. 4,513,963 discloses an exerciser including a tubular member having bearings provided within the tubular member. U.S. Pat. No. 4,043,553 discloses an exerciser including a pair of hand grips rotatably secured to an eccentrically weighted cross shaft.
Applicant's U.S. Pat. No. 6,488,613, the contents of which are hereby incorporated by reference, discloses an inertial exerciser device including first and second rotatably mounted weights, a chamber that at least partially encloses the weight system, and a grip mechanism for the user to grip the exerciser. The inertial exerciser device includes a spigot and yoke system to allow the spherical weights of the pendulums to rotate in the same plane. The method of exercising with this device is theoretically quite satisfactory. However, this exercise device may have the disadvantage that it is difficult to provide an equal mass for the two pendulums, as they have different shapes. Further, as a straight rod is rigidly connected to the spigot, the point of attachment of the rod to the spigot is subjected to excessive torsion forces, reflected in Lissajous lines, while in use. These excessive torsion forces may tend to induce material fatigue that will debilitate the pendulum's structural resistance, particularly if the elements are formed of molded plastic material, such as, for example, polyethylene. Additionally, since the pendulums of U.S. Pat. No. 6,488,613 are not exactly alike, they must be produced by two different manufacturing processes. Thus, manufacture of this device does not produce economies of scale. Further, in the case in which plastic material is used, two different molds must be used, which produces higher fixed costs and shorter production runs. Another consideration is that it is more aesthetically pleasing to provide a matched set of pendulums, since the pleasant appearance of a product is important for marketing and in the market place. Additionally, elimination of the circular cover would provide a lighter and more economical device to produce.
Applicant's U.S. Pat. No. 6,776,742 discloses a handheld exerciser including a handle to be gripped by a user, and at least two weights which are one of freely rotatably mounted and freely orbitally mounted about an axis passing through the handle.